Process of drilling wells



J. A. AND G. A. FITZPATRICK. PROCESS OF DRILLING WELLS.

APPLICATION FILED Nov. 22. 1919.

Patented Oct, 18,

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J. A. AND G. A. FITZPATRICK. PROCESS OF DRILLING WELLS.

1,394,192. APPLICATION FILED NOV=22, I919- 2 SHEETS-SHEET 2.

XQM I GEORGE 4 F72 PA 7"/?/ cm 77? 7 TOR/VE YS for its object to provide a same strata and hole and showln UNITED STATES PATENT OFFICE.

JOHN A. I'I'IZPATBICK AND GEORGE A. FITZPATBICK, OI SANTA ANA, CALII'OBNIL 1 394 192. Specification of Letters Patent.

Patented Oct. 1 8, 1921. Application illed November 22, 191 9. Serial No. 838,937.

To aZZ whom it may concern:

Be it known that we, -JOHN A. FITZPAT- RICK and GEORGE A. F 'rzPA'rRIoK, citizens of the United States residing at Santa Ana, in the county of drange and State of California, have invented new and useful Improvements in Processes of Drilling Wells, of which the following is a specification.

' This invention relates to water and oil wells and has for its object to improve the the well casing is run, method for drilling, developlng and bringmg into the suction perforations formed in ing in water and 011 wells, and further has the casing.

method for the It is, therefore, one of the objects of our will enable the lnvention to provide a method f draining of the rendered useless by the caving in of the walls of the well again it is well- 0 a well is deterthe strata of construction of a well that maximum efficiency in the subterranean reservoirs, and also that will ed result in the production of a well which will against crushing be operative for an extensive per od by elimof the well inating the ordinary causes tending to choke a well of the well inlets before the subterranean res- To that end, the process involves the first ervoirs have been fully exhausted, and with step, as seen in Fig. 1, of drilling the hole these and other objects in view the inven- 2 to the depth required as will be indicated tion consists of the method of developing according to the results shown and constructing a well, and the well rokept during the drillingof the duced thereby, forms of which are ilusho e 2 is trated in the accompanying drawings and larger diameter than the casing 3 that is described and claimed herein.

Figure 1 is a sectional view showing grammatically the earth strata penetrated by a well hole.

Fig. 2 is a vertical section illustrating lzhe a s ep of the process in which the sand rom the hole is being ejected and the inserted casing is being jacketed in a sheath of gravel.

Fig. 3 illustrates the same hole and shows the casing perforating step of the process.

Fig. 4 is a vertical sectional view of the same hole showing the step of developing the well.

maxlmum flowing efliclency.

rotary drill apparatus although the hole may be drilled by any other suitable ap ratus as determined by the nature of earths strata.

After the hole has been sired depth and has been diameter, as in Fig.1, th the hole. being provided with a cross sectional area 2 is larger than the lower cross sectional area 2 for the purpose of forming large passa e ways, relatively, around Fig. 5 is a vertical section showing the the casing 3 w ich comprises, preferably, well casing in completed condition with the the upper casing ortion 3 known as the usual operating pump installed in the pump pump p1t and the ower suction stringer 3 pit. e pump p1t sectlon 3 may be of any de- Fig. 6 is a vertical section showing strata sired length and is connected to the water the driven to the degiven the desired e upper portion of of earth diiferent from that in 1 and or lower stringer 3 as by a reducer 3. illustrating the method as followe to pro- During the drilling of the well to produce an oil well. duce the hole 2 in Fig. 1, the walls of the Fig. 7 is a detail view of the shoe or foot hole are usually sustained by the pressure closure for the main casing. of the mud 4 indicated therein and which is In the ordinary process of drilling either left in the hole durin the drilling operashallow or deep wells either for water or tion. After the hole has been drilled the for oil it is well-known that after the hole drilling apparatus is withdrawn leaving the has been sunk and a casing inserted in the mud 4 in the, hole and the casing 3 is then hole frequently the casing is crushed owing next assembled and lowered into the hole 2 t0 the excessive pressure of the eavlng earth to the desired depth, or in close proximity,

livered from any suitable source as a at its lower end to the bottom of the well; the lower end of the casing preferably be ing provided with a foot or shoe 5 wit the downwardly opening perforations 6, Fig. 7, to prevent any material quantity of the mud in the well from passing upwardly into the casing.

After the casing 3 has been lowered to the desired degree a reducer or swage nipple 7 is attached thereto and to this there is connected a water supply pipe 8 to which water under considerab e pressure is deforce pump, this water being driven downwardly through the casing as indicated by the arrows, Fig. 2 and dlscharging through the erforated shoe 5 thus passing outwardly into the bottom of the well and rising upwardly in the considerable space surrounding the casing so that the upwardly moving stream of water will carry the mud 4 forme by the previous drilling and also will tend by attrition from its circulation to work its into the various sand strata wa laterally through which the well hole in icated at 8 2 may extend.

The attrition or scouring movement of the flowing water thus loosening the sand in the adjacent pockets and layers will carry the loosened sand upwardly and discharge the same as at 10 at the top of the well.

An im ortant feature of this invention is the continuous introduction into the well hole, while the water is being forced throu h the supply pi e and down the caslng, o a mass of grave indicated at 11 this being of suitable size and assorted. We have found actual practice that gravel of threefourths of an inch diameter and less is preferable for the purpose and the gravel is introduced into the to of the well hole in the spacing surroun in the casing 3 and will gravitate downwar ly through the l1quid mass of mud and waterreplacing the sand, silt and other line particles by settling upon the bottom of the well hole and gradually building up as the water displaces the finer particles.

As clearly illustrated at 12, the gravel will flow laterally into such pockets as may have been. assed through by the drill hole and will fi these pockets and also will fill the cavities produced by the erosion of the sand strata, this filling taking place in successive upward depos1t of the gravel during the continued washing of the well hole casing by the stream of water forced through the until the hole has been filled to the to with the gravel.

t has been found that the gravel will thus settle laterally into the pockets by actual observation in drilling a well and developing the same according to this process by keeping a7 log of the steps and in which it has been shown that a very. considerable quantity of gravel will often be required at some particular level in the well without any appreciable change in the height of the pi e or jacket of gravel about the casing and on the contrar when the gravel appears to be filling on y the space immediately about the jacket the change is rapidly noted as determined by the uantity of ravel that ma be poured into t e hole.

aving thus 'fil ed the chambers or pockets in the strata and filled the space in the well hole about the casing 3 so that a gravel filtering jacket and mass is produced up to the top of the well then the pump connections are removed including the cap 7 and any suitable erforatin apparatus indicated at 15 is introduce into the well casing, and the lower portion or strin er 3 is, preferably, perforated as at 13 om the top of the stringer below the reducer 3 down to. the bottom of the casing. These perforations may be of any suitable proportions and size and are, preferably, less in one dimension than the size of the larger lglrslivels in the 'mass charged into the well After the perforating has been completed the perforating apparatus is removed and then the well is developed by introducing 1nto the casing 3 a suction pipe 16,

- preferably, of less diameter than the diamethe suction pipe of the water in the casing and of the water surrounding the casing in through the perforations 13 of the casing. As the casing and gravel jacket is cleaned of sand by the air lift the pipe ,16 will be lowered in successive steps until the entire depth of the well has been washed. The result will be that all of the sand that may have accumulated in the casing is removed from the same by the air lift method and discharged at the outlet 20 of the suction pipe. Thisdeveloping of the well continues for a suitable length of time until it is proved that the well casing and the surrounding well chamber and pockets which are filled with gravel have been washed clear of sand and only clear fluid is being discharged at the outlet 20.

After this development of the well the suctlon pipe and the air lift pipeare removed from the wellcasing and any suitable form of pumping-apparatus is connected to the casing, as for lusts/hoe by inserting a centrifugal pump 21 into the pump pit or section 3 0f the casing, and after the pump is set in operation the well will continue to flow with maximum capaciity and With freedom from sand.

When this method is followed for bringing in an oil well as is indicated in Fig. 6, it. is desirable to prevent infiltration of water with the oil from the water bearing strata above the oil bearing strata indicated at 25, Fig. 6; and to that end, in the original drilling of the hole 3 for an oil well after the drilling has been continued down to a suitable depth and taken through the usual water bearing strata there is introduced into the hole an outer casing or shell 30 of somewhat less diameter than the upper portion of the well hole, and this casing is then externally packed with a cement jacket 31 to prevent the downward flow of the water from the upper levels into the lower portion of the well hole indicated at'82 below the jacket and easing 31-30.

The jacket and easing are usually placed in a stratum of earth'that is impervious to Water flow. From this it will be seen that by our method it is possible to perforate the lower end of the casing in the oil well from the portion immediately below the jacket 31 to the foot of the casing section so that the oil reservoirs irrespective of their depths can all be drained into the suction apertures of the casing and yet the inflow of water from the upper layers be eliminated. Again by jacketing the suction end of the casing with the gravel 11 as above described it will be seen that sand will be kept out of the casing and the oil will have free passage through the interstices in the gravel mass.

By developing a well as disclosed in the above it will be seen that the well casing can readily be brought to a true vertical or plumb position within the well hole since the latter is of sufficiently large diameter from top to bottom to permit the free sus pension of the casing within the same and,

therefore, the usual difliculty encountered by the jamming of the pump within the casing is overcome. A further advantage of this plumb position is in the reducing of wearing in the bearings.

While it has been stated that gravel is used in the method of producing the desired filter yet it is understood that any other filtering medium or agency may be utilized.

In order to secure the solid packing or settling of the gravel mass while the same is being charged into the hole the well casing, which is flexibly suspended in the well hole, can be and sometimes is rotated.

Various changes may be made without departing from the spirit of our invention as claimed,

We claim:

1. That method, of constructing a well wherein a casing is lowered into a hole of greater diameter, from top to bottom than the casing, forcing water down the casing to the bottom of the well so it flows upward in the outer chamber and washes it out, and filling the washed well hole with assorted bodies to form a filtering jacket about the casing, thereafter perforating the casing to form suction holes.

2., That method, of constructing a well wherein a casing is lowered into a hole of greater diameter, from top to bottom than the casing,.forcing water down the casing to the bottom of the well so it flows upward in'the outer chamber and washes it out, and filling the washed well .hole with assorted bodies to form a filtering jacket about the casing, thereafter perforating the casing to form suction holes, and then producing a suction through the holes by an air lift to rapidly develop the Well by draining off the small particles from the filtering jacket so that the liquid from the strata may per-j colate readily to the well casing.

In testimony whereof we have signed our names to this specification,

JOHN A. FITZPATRICK. GEORGE A. FITZPATRI-CK. 

